The physical dimensions of this M. pergandei
nest were difficult to determine. The crater-like structure was approximately 0.76m / 2.5 ft wide, but was composed entirely of plant material discarded by the ants (chaff). I expected to find a raised sand and gravel structure beneath this fluffy chaff (as would be typical for this species), but it wasn't there. The nest entrance is located in the shaded area, at center. If you enlarge this image (by hovering your mouse cursor over it, and selecting a larger size from the menu), you can see foraging workers streaming out toward the right.